1. Field of the Invention
This invention relates generally to an automated apparatus for the high-speed delivery of precisely measurable quantities of a variety of viscous liquid materials having varying characteristics to a plurality of containers in a sanitary environment.
2. Description of the Related Art
A wide variety of sanitary filling operations, especially in the pharmaceutical and food processing industries require high-speed fluid metering systems capable of delivering precisely measured quantities of viscous liquid materials at accurate flow rates to various locations and in a sanitary manner. Typical filling operations involve a delivery apparatus for delivering viscous liquid material to a viscous liquid material manifold, and a plurality of fill heads adapted to simultaneously dispense the viscous liquid material into a batch or plurality of empty vessels (i.e., bottles, containers or the like) to a plurality of fill heads.
Modern sanitary filling operations require high speed operations involving pressure having ranges of 400 pounds per square inch (psi) or greater and pumping cycles in the range of about 20–200 cycles per minute and preferably 60–160 cycles per minute to provide constant flow. Accordingly, in such operations, precise and accurate delivery of the viscous liquid material is critical.
Moreover, such sanitary filling operations must meet the performance requirements established by the U.S. Food and Drug Administration (FDA), which require that machines used to fill containers with liquid food or drug materials must be sterilizable, and readily cleaned of liquid materials which might be trapped in cavities within machine parts, and thereby providing a growth media for microbes. Accordingly, a goal in the design and construction of in-line filling machines for liquid food materials is that to provide an attachment as well as components suitable for cleaning-in-place (CIP) operations.
Heretofore, pump delivery systems that pump viscous liquid materials to various sources in precise and accurate flow rates are difficult to achieve due to the pulsing, surging, or hydraulic shock generated by the output of the pump mechanism. Such pulsing, surging or otherwise hydraulic shock is undesirable since it typically results in hydraulic hammer in process lines, large pressure fluctuations, excessive wear and increased cost of maintenance of pumps and instruments, inaccurate flow rates during delivery operations, which results in increased material costs and time. Moreover, conventional fill heads do not permit adjustable regulation of the flow rate of the viscous liquid material during filling operations at a point between the inlet to the fill head and the fill head chamber. Such fill heads also lack adjustable regulation of the flow rate in accordance with physical characteristics such as density, viscosity, compressibility and pump pressure of the viscous liquid material being dispensed. Such fill heads also permit turbulent flow during filing operations that thereby result in the dispensing of imprecise amounts of viscous liquid material.
What is presently needed is an apparatus that is equipped for high pressure and high-speed fluid metering and pumping (i.e., pressure ranges of 400 pounds psi or greater and pumping cycles in the range of about 20–200 cycles per minute and preferably 60–160 cycles per minute) in delivering precise measured quantities of viscous liquid materials at accurate flow rates. Such an apparatus should also be adaptable for use in sanitary filling operations and also include a pump pulsation dampening assembly that also meets the cleaning-in-place standards required by the FDA. Such an apparatus should also be adaptable to automatically monitor and adjust the air-to-liquid ratio inside a pump pulsation dampening assembly in response to the duration and intensity of the pulsating fluid flow from the pump mechanism. Such an apparatus should also accommodate varying viscosities of the metered viscous liquid material in addition to variations in compressibility due to the location of each fill valve relative to the fill station which receives the viscous liquid material from the fluid manifold as well as various parameters involved during a filling operation.